/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.transforms;



import com.bff.gaia.unified.sdk.util.SerializableUtils;



import javax.annotation.Nullable;

import java.io.Serializable;



/** Useful {@link SerializableFunction} overrides. */

public class SerializableFunctions {

  public static <InT, OutT extends Serializable> SerializableFunction<InT, OutT> clonesOf(

      final OutT base) {

    return input -> SerializableUtils.clone(base);

  }



  private static class Identity<T> implements SerializableFunction<T, T> {

    @Override

    public T apply(T input) {

      return input;

    }

  }



  private static class Constant<InT, OutT> implements SerializableFunction<InT, OutT> {

    @Nullable

	OutT value;



    Constant(@Nullable OutT value) {

      this.value = value;

    }



    @Override

    public OutT apply(InT input) {

      return value;

    }

  }



  public static <T> SerializableFunction<T, T> identity() {

    return new Identity<>();

  }



  public static <InT, OutT> SerializableFunction<InT, OutT> constant(@Nullable OutT value) {

    return new Constant<>(value);

  }

}